Paper machinery



Oct. 24, 1961 J. BAXTER, JR I 3,005,746

PAPER MACHINERY Filed June 30, 1958 Fl G -1 O [7 l7 /3 4 4 /z 40% I 33/ 35 2O FIG-2 4/ Y 35 32 r 22 l u 56 25 FIG-5 so 26 INVENTOR.

JOSEPH BAXTER,JR.

W Mfi ATTORNEYS s,os-,746 PAPER MA-GHINERY Joseph Baxter,Jr.,,Franlrlin,- Ohio, assignor to Thelilacli Ciawson- Company, .l-lamilton, Ohio, a corporation of 'I'Zheinvention is particularlyconcerned with the relation between" the air currents which. exist in the int-- rn'ediat'e vicinity of the-initial forming zone of Fourdrinier; type aper machines. and the: quality of? the sheet pro-*- duced thereon. More specifically, as the-bare wire appreaches theforming? zone, it tends to carry a certain amount of wirrdage therewith, some. of which is likely to" be trapped. between: the breast rolland the lower slice lip as the stock: is deposited ctr-the wire. Such trapped bubbles of airtherefore interfere with the: desired uni form deposit of stock onthe wire and also create an undesirable boiling. action: as they: attempt to' break. free of: the liquid stock. Itwill' also be apparent that these conditions increase in: severity with increase inthe speed of. operation of thefmachine.

Itis a: primary object of the. present invention to over come the: difiiculties outlined above by. the provision of afou-rdrinier paper machine of. such structure and mode or. operation: that it. isnot possible for air to be trapped by or entrained withxtlie stock as it is. discharged onto the wire.-

It is a specific object of this. invention to provide: a

Fou-rdrinier type paper: machine wherein a steam compartnrent is located in such. relation with the slot between the slice lip and the breast roll that steam will continuously bleed through this slot to prevent trapping and entrainmentof air with the: stock asit impinges on the formingwire.

Anadditional object: of the invention is to provide a Fourdrinier. type paper machine as outlined: above wherein the steam: compartmentis so located and arranged with. relation to the portion of the breastroll approaching the slice lip that the steam: serves also to stri the wireof all windage: before the wire enters the forming zone.

It is also an obiectof theinvention. to provide a steam compartment structure for a Fourdrinier' type paper machine' as outlined abovewhich is readily applicable to existing paper machines and will. afiordthereon the same advantages in operation as when it is built directly into a new machine.

. Additional objects: and advantages of the invention Willi be: apparentfrom the following description, the accompanying drawings and the. appended claims.

In the drawing:

1. is a: somewhat diagrammatic view inside ele' vation showing an illustrative headbox constructed in accordance with the invention;

HG. 2 is tin-"enlarged fragment of- FIG; 1 in vertical section through the lower slice lip; and

FIG. 3 is a fragmentary perspective view of the same portion of the headbox FIG. 2 with; the breast roll removed;

Referring to the drawing, which illustrates a preferred embodiment of the invention, the headbox indicatedgenorally at in 1 includes a flow chamber 11 having a stock inlet connection 12 at the back thereof from which the stock flows to the slice outlet 13 defined by the upper and lower slice lips 14 and 15. The stock inlet indicated generally at 16 may be of any suitable structure and does not constitute a part of the present atent" 4* 2 invention; and similarly the headbox may incorporate: any suitable' arrangement of rectifier rolls 17.

FIGS: l and 2 show a fragment of the forming wire 20 approaching and passing. around the breast. roll 22 to receive stock from the outlet. 13, andthe invention is: co'ncernedwith the air currents in the immediate vicinity (if the outlet-13, particularly with preventing the trap ping and entrainmentof air with the stock as the steels is first deposited on the wire and breast roll. In accordance with the invention, walls 25 and 26 cooperate with-the underside of the lower" slice lip 15 to define: a= eempartm nt: 30 whichiexte'nds. the full length of the; breast roll' 22, and the front wall of which is formed by th ang ular portion. of the: breast roll between. theoutefie'dges-ofthe: slice lip 15 and Wall 25. Each end; (it this compartment 30 is. closed by an end wall 32 which includes asuitable' seali assembly 32;- engaging the surfaeeot the breast roll 22, butneither the lip 15 nor Wall 25- touches the breast? roll, and instead these parts; are arr' 'ang'ed in closely spaced relation to provide definite slots 35 and 36 thercbetwe'c'n.

Provision is made for supplying the interior of the: compartment 30 with steam under maintained pressure sufficient to assure continuous substantially uniform discharge thereof through both'o'f'the slots 35' and 36. More specifically, the objectives of the invention. are achieved: itxthestearn pressure within the compartment 36 ismaine tainted continuously slightly in excess of. the pressure; generated by the winda'g'e' on the wire at the inlet slot. 3'6-to' the compartment 30', since under such conditions} the-steamwill effectively strip the wire of entrained air. as it enters: the-compartment 30. Inaddition, the steam: whichescapes through. the exit slot 35' serves both to. luhr'ica'teth'e slice lip andpfarticularly to prevent trapping; of a'ir between'the stock and the-breasttroll. by acting as. a displacing forc e blocking air from. access to the wire at this location. Uesired conditions for suchcontrol' escape of steam are obtained' byextending a steam supply pipe 40 throughout substantially the' full length of the compartment 30 andby providing this steam pipe with multiple outlets 4 1'- which preferably. are directed away from the surface ofthe br'east roll. Thus with these outlets arranged shown iii-FIGS.) and 3 to discharge toward the compartment wall 26,-this' wall. actsas abaffie to absorb the discharge: velotiity of the 'steam and convert it to a maintained presstif'' condition throughout the compartment for the de' sired controlled bleeding of steam through both. ofthe slotsdfi and 36.

It: will be apparent in view ofthe above explanation oftheprinc'iples ofithis invention that specific steam sup-- ply" and pressure conditions are readily calculated in ac:- surname with the size and speed of a given paper. ma chine, with the requirements increasing as the speed of the: machine maybe increased. It is also significant to note that while the steam which is discharged through the slot 35 will virtually entirely be condensed with the stock on the. wire, this in itself has further advantages.- In' particular, the condensing of the steam will necese sarily produce a corresponding-increase in the temperature' of the stock wherein the steam is absorbed, with resulting lowering of the viscosity of the water and in?- creased ease of draining. It also appears that to the: extent that condensation of the steam takes place directly withinthe wire, it will further serve to facilitate drainage through the wire.

It should further now be apparent that constructions:- embodying the invention are as readily adapted to exists ing paper machines as they are built into' new machines: This is particularly the case with the lower" slice. lip lending itself to use as one wall of the steam compartment, and also since neither the volumetric size of this compartment nor the specific slot clearances between its walls and the breast roll are of more than practical significance. The invention accordingly olfers important practical and economic advantages with minimum requirements of both initial and maintenance cost.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. In a paper machine including a headbox, a breast roll around which the forming wire travels, and a lip forming one side of thhe outlet through which the stock flows from the headbox onto the breast roll, the combination of means cooperating with said lip to define a compartment on the opposite side of said lip from said outlet with one side thereof formed by the portion of said breast roll approaching said outlet, a supply source of steam under pressure, and means forming a connection leading from said supply source to said compartment for continuously introducing steam into said compartment at a pressure sufiicient for continuous discharge thereof between the outer edge of said lip and said breast roll.

2. In a paper machine including a headbox, a breast roll around which the forming wire travels, and a lip forming one side of the outlet through which the stock flows from the headbox onto the breast roll, the outer edge of said lip and said breast roll being in closely spaced relation providing a slot therebetween, the combination of means defining a compartment located on the opposite side of said lip from said outlet and communicating directly with said slot, a supply source of steam under pressure, and means forming a connection leading from said supply source to said compartment for continuously introducing steam into said compartment at a presure sulficient for continuous discharge thereof through said slot. 3. In a paper machine including a headbox, a breast roll around which the forming wire travels, and a lip forming one side of the outlet through which the stock flows from the headbox onto the breast roll, the outer edge of said lip and said breast roll being in closely spaced relation providing a slot therebetween, the combination of means including a wall and the opposite side of said lip from said outlet defining a compartment including as one side thereof the portion of said breast roll between said wall and said lip, said wall being in closely spaced relation with said breast roll providing a slot therebetween, means forming seals between the ends of said compartment and said breast roll while maintaining said slots between said breast roll and said lip and wall, a supply source of steam under pressure, and means forming a connection leading from said supply source to said compartment for continuously introducing steam into said compartment at a pressure sufiicient for continuous discharge thereof through said slots.

4. In a paper machine including a headbox, a breast roll around which the forming wire travels, and a lip forming one side of the outlet through which the stock flows from the headbox onto the breast roll, the combination of means including said lip and an angular portion of the surface of said breast roll approaching the outer edge of said lip defining a compartment extending the length of said breast roll, a conduit extending substantially the full length of said compartment and having multiple outlet means in the side thereof facing away from said breast roll and said lip, a supply source of steam under pressure, and means connecting said conduit to said supply source of steam to maintain said compartment filled with steam under pressure sufiicient for continuous discharge of said steam between the outer edge of said lip and said breast roll.

with the outer edge thereof in closely spaced relation with said breast roll providing a slot therebetween, walls cooperating with said lip and the adjacent portion of said breast roll to form a compartment extending below said lip for substantially the full length of said breast roll, means forming seals between the ends of said compartment and said breast roll while maintaining said slot between said lip and said breast roll, a supply source of steam under pressure, and means forming a connection leading from said supply source to said compartment for continuously introducing steam into said compartment at a pressure suflicient for continuous discharge thereof through said slot.

6. In a paper machine including a headbox, a breast roll around which the forming wire travels, and means.

including a lower slice lip defining an outlet through which the stock fiows from the headbox onto said breast roll, the combination of means maintaining said lip with the outer edge thereof in closely spaced relation with said breast roll providing a slot therebetween, means including a bottom wall cooperating with said lip and the angular portion of said breast roll between said bottom wall and said lip to form a compartment extending below said lip for substantially the full length of said breast roll, said bottom wall and said breast roll being in closely spaced relation providing a slot therebetween, means forming seals between the ends of said compartment and said breast roll while maintaining said slots between said breast roll and said lip and bottom wall, a supply source of steam under pressure, and means forming a connection leading from said supply source to said compartment for continuously introducing steam into said compartment at a pressure suflicient for comv tinuous discharge thereof through both of said slots.

7. The method of eliminating air bubbles from the forming wire of a paper machine immediatelyprior to the delivery of stock thereto which comprises applying steam to said wire under controlled pressure conditions causing said steam to displace air from within the interstices of said wire, and maintaining said steam pressure conditions throughout said wire and in the immed ately surrounding atmosphere until the stock is applied to said Wire to displace said steamtherefrom.

8. The method of eliminating air bubbles from the forming wire of a paper machine during travel thereof around the breast roll to the initial forming zone where thestock is applied thereto, which comprises the steps of supplying steam to a substantially enclosed space bounding and immediately ahead of the junction between the breast roll and the forming zone under controlled pressure conditions causing said steam to displace air from the interstices of said wire and to remain within and along said wire during entry of said Wire into the forming zone for displacement from said wire by the stock.

References Cited in the file of this patent UNITED STATES PATENTS 1,867,930 Traquair July 19, 1932 2,255,951 Tomtlund Sept. 16, 1941 2,276,877 Rolls Mar. 17,1942 2,344,281 Berry et a1 Mar. 14, 1944- 2,615,374 Malkin Oct. 28, 1952 2,666,370 Bachus Jan. 19, 1954 2,744,452 Niks May 8, 1956 2,756,651 Lee July 31, 1956 

7. THE METHOD OF ELIMINATING AIR BUBBLES FROM THE FORMING WIRE OF A PAPER MACHINE IMMEDIATELY PRIOR TO THE DELIVERY OF STOCK THERETO WHICH COMPRISES APPLYING STEAM TO SAID WIRE UNDER CONTROLLED PRESSURE CONDITIONS CAUSING SAID STEAM TO DISPLACE AIR FROM WITHIN THE INTERSTICES OF SAID WIRE, AND MAINTAINING SAID STEAM PRESSURE CONDITIONS THROUGHOUT SAID WIRE AND IN THE IMMEDIATELY SURROUNDING ATMOSPHERE UNTIL THE STOCK IS APPLIED TO SAID WIRE TO DISPLACE SAID STEAM THEREFROM. 